Most of the hackers use linux is that true?

I have heard that linux OS is developed by the hackers,I have heard from a variety of people that hackers use linux, is that true?am not sure about knowledge regarding the Linux help hackers, guys could tell me that what is true have you heard such comments if so it is true please explain to you why the hackers use as well as develop Linux, why is it called open soucre? happy my lotting...